The invention relates generally to the disposal of energetic materials and more particularly to the deactivation of hydrazines, such as unsymmetric dimethyl hydrazine (UDMH) which are used as propellants. When combined with nitrogen tetroxide (N.sub.2 O.sub.4) the reaction with UDMH releases a great amount of energy by the reaction: EQU N.sub.2 H.sub.2 (CH.sub.3).sub.2 +2N.sub.2 O.sub.4 .fwdarw.3 N.sub.2 +4H.sub.2 O+2 CO.sub.2
This reaction has been used in liquid fueled rockets and, consequently, the disposal of such hydrazines represents an important problem at the present time. Hydrazines alone may also be used as propellants where they are catalytically decomposed without oxidizers being present.
UDMH could be disposed of by incineration, decomposition in supercritical water, or by the above reactions, but it would be preferable if the products of the disposal method had commercial value. It was the purpose of the present inventors to develop a method for convenient disposal of hydrazine (N.sub.2 H.sub.4) and substituted hydrazines such as UDMH which has the least adverse impact on the environment while at the same time produces valuable by-products.
It has been known that substituted hydrazines can be hydrogenated to ammonia and amines, see Catalytic Hydrogenation over Platinum Metals, Rylander, Academic Press 1967, p. 134-135.
Hydrogenolysis of substituted hydrazines over Rainey nickel catalysts was reported by Lunn et at. in Environ. Sci. Technol. Vol. 13, No. 4, 1983. Hydrogen was generated insitu by the reaction of KOH with an aluminum-nickel alloy.
Decomposition of hydrazine is discussed by Armstrong et al. in U.S. Pat. No. 4,122,671. Noble metal catalysts were shown to be effective so that no oxidizer was required.
Destruction of nitrogen-containing explosives has been the subject of various disclosures. German patent publication DE 413147-A1 discusses the hydrogenation of nitro-aromatic explosives in the presence of a solvent, hydrogen, and a catalyst at a temperature of40.degree.-100.degree. C. U.S. Pat. No. 4,661,179 discloses a process for destroying waste explosives containing nitro, nitrate, or nitroamino groups.